Hybrid wafer bonding method and structure thereof

Abstract

A hybrid wafer bonding method includes providing a first semiconductor structure and providing a second semiconductor structure. The first semiconductor structure includes a first substrate, a first dielectric, and a first via structure. The first via structure includes a first contact via and first metal impurities doped in the first contact via. The second semiconductor structure includes a second substrate, a second dielectric layer, and a second via structure. The second via structure includes a second contact via and second metal impurities doped in the second contact via. The method further includes bonding the first semiconductor structure with the second semiconductor and forming a self-barrier layer by an alloying process. The self-barrier layer is formed by a multi-component oxide corresponding to the first and second metal impurities.

What is claimed is: 
     
       1. A hybrid wafer bonding structure, comprising:
 a first semiconductor structure comprising:
 a first dielectric layer, and a first via structure in the first dielectric layer, the first via structure comprising a first contact via surface; and 
 
 a second semiconductor structure comprising:
 a second dielectric layer, and 
 a second via structure in the second dielectric layer, the second via structure comprising a second contact via surface, 
 wherein: 
 the first contact via surface of the first semiconductor structure is bonded with the second contact via surface of the second semiconductor structure, 
 a self-barrier layer surrounding the second contact via surface along a lateral direction and extending into each of the first contact via surface and the second dielectric layer in a vertical direction, wherein the self-barrier layer contains a multi-component oxide, 
 the first via structure comprises first metal impurities doped in a bulk region of the first via structure, and 
 the second via structure comprises second metal impurities doped in a bulk region of the second via structure. 
 
 
     
     
       2. The structure according to  claim 1 , wherein:
 each of the first dielectric layer and the second dielectric layer comprises silicon oxide, and 
 the multi-component oxide containing Si, O, and at least one of Al, Mn, or Ag. 
 
     
     
       3. The structure according to  claim 2 , wherein:
 the multi-component oxide is silicon aluminum oxide. 
 
     
     
       4. The structure according to  claim 1 , wherein:
 the first semiconductor structure further comprises: 
 an insulating layer on a side of the first dielectric layer away from the second dielectric layer, and 
 a barrier film between the insulating layer and the first dielectric layer, wherein the barrier film comprises silicon nitride or nitrogen-doped silicon carbide. 
 
     
     
       5. The structure according to  claim 4 , wherein:
 a conductive layer is in the insulating layer and connects to the first via structure in the first dielectric layer. 
 
     
     
       6. The structure according to  claim 1 , wherein:
 the first semiconductor structure further comprises:
 an insulating layer on a side of the first dielectric layer away from the second dielectric layer, and 
 a conductive layer in the insulating layer, 
 wherein:
 the first via structure comprises a first contact via with the first contact via surface and a first element connecting to the first contact via, the first element further connecting to the conductive layer, 
 an orthogonal projection of the first contact via on a lateral plane with respect to the vertical direction is greater than an orthogonal projection of the first element on the lateral plane. 
 
 
 
     
     
       7. The structure according to  claim 1 , wherein:
 the first via structure in the first dielectric layer further comprises:
 a barrier layer adjacent to the first dielectric layer, and 
 a seed layer over the barrier layer, wherein the barrier layer is made of a material comprising Ti, Ta, TiN, TaN, TiSiN, or any combination thereof. 
 
 
     
     
       8. The structure according to  claim 1 , wherein:
 the first via structure comprises a first contact via with the first contact via surface and a first element connecting to the first contact via, 
 the second via structure comprises a second contact via with the second contact via surface and a second element connecting to the second contact via, and 
 an orthogonal projection of the second contact via on a lateral plane with respect to the vertical direction is greater than an orthogonal projection of the first element on the lateral plane. 
 
     
     
       9. A semiconductor structure, comprising:
 a first dielectric layer; 
 a first via structure in the first dielectric layer; 
 a second via structure on a first portion of a surface of the first via structure; 
 a self-barrier layer containing a multi-component oxide and comprising a first self-barrier portion disposed into a second portion of the surface of the first via structure, and 
 a second dielectric layer on the self-barrier layer and the first dielectric layer,
 wherein the self-barrier layer further includes a second self-barrier portion disposed into the second dielectric layer in a vertical direction, 
 the first via structure comprises first metal impurities doped in a bulk region of the first via structure, and 
 the second via structure comprises second metal impurities doped in a bulk region of the second via structure. 
 
 
     
     
       10. The structure according to  claim 9 , wherein:
 the first via structure comprises a first element and a first contact via on the first element, 
 the second via structure comprises a second contact via on a first portion of a surface of the first contact via and a second element on the second contact via, 
 a first contact via surface of the first contact via fully covers the self-barrier layer and a second contact via surface of the second contact via, and 
 an orthogonal projection of the second contact via on a lateral plane with respect to the vertical direction is greater than an orthogonal projection of the first element on the lateral plane. 
 
     
     
       11. The structure according to  claim 10 , further comprising:
 a first barrier film under the first dielectric layer, wherein the first element is through an entire thickness of the first barrier film, and bottom surfaces of the first barrier film and the 
 first element are coplanar with each other. 
 
     
     
       12. The structure according to  claim 11 , further comprising:
 a first insulating layer, wherein the first barrier film is between the first insulating layer and the first dielectric layer, and 
 a first conductive layer in the first insulating layer and connecting to the first element. 
 
     
     
       13. The structure according to  claim 10 , further comprising:
 a second barrier film over the second dielectric layer, wherein the second element is through an entire thickness of the second barrier film, and top surfaces of the second barrier film and the second element are coplanar with each other. 
 
     
     
       14. The structure according to  claim 13 , further comprising:
 a second insulating layer over the second barrier film, and 
 a second conductive layer in the second insulating layer and connecting to the second element. 
 
     
     
       15. The structure according to  claim 9 , wherein:
 the self-barrier layer surrounds an outermost surface of the second via structure along a lateral direction, and 
 the self-barrier layer is within an outermost surface of the first via structure along a lateral direction.